Cellular wireless communication devices, such as a mobile phones, personal digital assistants, and other wirelessly equipped devices, have become increasingly common in recent years. In general, a cellular wireless device communicates over an air interface with a base station, which provides the device with access to network resources, such as communication channels through which to interact with other devices or with network servers.
One of the more popular services for cellular wireless devices today is short message service (SMS) messaging, which entails communication of short alphanumeric messages or other binary data to or from a cellular wireless device. In practice, an SMS-equipped device may receive user input of a message and a message destination and may then send the message over the air interface to a base station for transmission in turn to the indicated destination. At the destination, the message can then be readily presented to a user or otherwise processed. In this manner, SMS messaging allows users to conveniently engage in quick back and forth communication with each other from virtually anywhere within cellular coverage. Further, SMS messaging can be used for assorted other purposes, such as delivery of news and advertisements, delivery of alerts, initiation of cellular data sessions, and conducting of group chat sessions, among numerous others.
In general, the air interface between a cellular wireless device and a serving base station may define various communication channels through which the device and base station can communicate with each other. “Forward” channels that carry communications from the base station to the device may include forward control channels such as paging channels for carrying page messages and forward traffic channels for carrying voice and other bearer data. “Reverse” Channels that carry communications from the device to the base station, on the other hand, may include reverse control channels such as access channels for carrying call origination requests and registration requests, as well as reverse traffic channels for carrying voice and other bearer data.
Under existing procedures, a cellular wireless device can transmit an SMS message to a base station over either a reverse access channel (R-ACH) or a reverse traffic channel (R-TCH).
On a reverse access channel, the device may transmit the SMS message in an “access probe” message in much the same way that the device would normally transmit a call origination request or registration request to the base station. Upon receipt of the SMS message, the base station or other serving equipment may then forward the SMS message to an SMS center (SMSC) for transmission in turn to a specified destination.
For reverse traffic channel transmission, on the other hand, if the device does not currently have an assigned traffic channel over which to communicate, the device may first transmit on a reverse access channel an origination message that seeks assignment of a traffic channel, and the device may then receive a traffic channel assignment from its serving base station. At that point, the device may then send the SMS message to the base station as bearer data over the assigned traffic channel, and the base station or other serving equipment may then forward the SMS message to an SMSC for transmission in turn to the specified destination.